For tax purposes, $55 of the $75 is tax-deductible. The balance of $20 is the fair market value of food/entertainment.
Upon clicking "Submit" you will receive an email confirming your RSVP. It will contain a link to PayPal to make your payment ($75/per attendee) and the mailing address to send a check if you chose that option. The party location will also be in the email. Please check your spam folder if you do not receive it.